(1) Field of the Invention
The present invention relates to a contents filtering method, a contents filtering apparatus, and a contents filtering program for filtering contents on a network, and more particularly to a contents filtering method, a contents filtering apparatus, and a contents filtering program for filtering contents against inappropriate use such as private use.
(2) Description of the Related Art
In the past several years, there has been pointed out the problem of private use of the Internet by employees of corporations during the working hours. Private use of the Internet tends to increase a wasteful traffic volume, reduce the working efficiency in corporations and the learning efficiency in schools, and lower the morals of employees, students, and pupils. The terms IAC (Internet Access Control) and EIM (Employee Internet Management) have been produced against the above background.
Recently, some corporations use software based on the concept of contents filtering to prevent employees of the corporations from obtaining inappropriate contents from the Internet via terminals in the corporations. The software for contents filtering includes URL (Uniform Resource Locator) filtering software (Internet filtering software) and e-mail filtering software.
The URL filtering software is software for regulating access to inappropriate home pages on the Internet. A computer in which the URL filtering software is installed monitors connections from the intranet to the Internet. The computer regulates requests for access to regulated URLs which have been registered in advance. Examples of the URL filtering software are WebSENSE (Net Partners Internet Solutions, Inc.) and Cyber Patrol (The Learning Company).
The e-mail filtering software is software for preventing confidential information from leaking out of corporations. A computer in which the e-mail filtering software is installed checks the contents of e-mail messages produced in the corporation and prohibits e-mail messages from being transmitted outside the corporation if those e-mail messages contain certain prespecified keywords. Examples of the e-mail filtering software include GUARDIAN WALL (Sumitomo Metal System Solutions Co., Ltd.) and MIMEsweeper (Content Technologies Co. Ltd.).
Using the above contents filtering techniques is effective to prevent the employees of corporations from inappropriately using the Internet connected to the corporations.
However, excessive limitations on access to the Internet give inconveniences to users, and the conventional contents filtering software has been not flexible enough in limiting access attempts. Specifically, since access to contents which have been specified as regulated contents has heretofore been inhibited at all times, users are unable to obtain those contents even if their acquisition is needed for business purposes.
For example, before an employee of a corporation makes a business trip to a foreign country, they may want to confirm, in advance, various pieces of information about the country, such as security, etc. If contents relating to “military forces and terrorism”, “racism”, “religion”, “crimes”, “travel”, etc. on the Internet are regulated against access from the corporation, then the employee may not possibly collect useful items of information from the Internet.
As described above, contents which are usually not related to business whatsoever may sometimes be necessary for business purposes. If access to these contents is fully inhibited, then the business efficiency may be lowered though the inhibition of access to those contents instead of increasing the business efficiency.
Access to the Internet may be limited only during certain hours, e.g., working hours. However, the recent trend of corporate employee management is shifting from working hours to other management indicators as evidenced by the introduction of the flex-time system and the payment-on-result system. Therefore, even if access to the Internet for private use is allowed during a certain period of time, such a policy is likely to depart from actual user needs.
There has been a demand for a system for allowing access to contents which have been specified as regulated contents insofar as such access does not excessively obstruct business activities.
While the URL filtering process and the e-mail filtering process have the same purpose of inhibiting private use of network resources, they have heretofore been operated and managed separately as they handle different entities. However, in order to perform contents filtering as a corporation's policy, it is necessary to control and manage the different filtering processes in a unified fashion.